Roads带限制条件的最短路算法

最新推荐文章于 2025-03-15 00:34:25 发布

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最新推荐文章于 2025-03-15 00:34:25 发布 · 2.1k 阅读

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该博客讨论了一个带有费用限制的最短路径问题。在包含城市和有向边的图中，目标是从城市1出发，找到一条总费用不超过K的最短路径到达城市N。博主分享了一种变形的Dijkstra算法，类似于BFS，通过优先队列来更新满足条件的最短路径。在错误示例中，问题出在Pair的排序上，正确做法是修正排序方式以确保找到符合条件的最短路径。

比较有启发意义的最短路

N cities named with numbers 1 … N are connected with one-way roads. Each road has two parameters associated with it : the road length and the toll that needs to be paid for the road (expressed in the number of coins).
Bob and Alice used to live in the city 1. After noticing that Alice was cheating in the card game they liked to play, Bob broke up with her and decided to move away - to the city N. He wants to get there as quickly as possible, but he is short on cash.
We want to help Bob to find the shortest path from the city 1 to the city N that he can afford with the amount of money he has.
Input
The first line of the input contains the integer K, 0 <= K <= 10000, maximum number of coins that Bob can spend on his way.
The second line contains the integer N, 2 <= N <= 100, the total number of cities.
The third line contains the integer R, 1 <= R <= 10000, the total number of roads.